[U-Boot] [PATCH] usb: composite: Fix max packet size for USB3.0
Marek Vasut
marex at denx.de
Thu Dec 13 13:24:32 UTC 2018
On 12/13/2018 10:46 AM, Siva Durga Prasad Paladugu wrote:
> For USB3.0, the max packetsize for GET_DESCRIPTOR should be
> sent as exponent value for 2. This means for 512, max packet
> size should be filled with 9(2^9=512). Also, fill the USB
> version field with 3.0 if speed is negotiated to Superspeed.
> This fixes the issue of DFU gadget download failure with
> superspeed. Without this patch, the max packet size is
> overflowed to zero as the bMaxPacketsize is of u8 and hence
> host is not able to detect this device.
>
> Signed-off-by: Siva Durga Prasad Paladugu <siva.durga.paladugu at xilinx.com>
> Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
> ---
> Changes from RFC:
> - Fixed typo in description as per comment.
> ---
> drivers/usb/gadget/composite.c | 17 +++++++++++++++--
> 1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
> index 5106cc5..c7e7623 100644
> --- a/drivers/usb/gadget/composite.c
> +++ b/drivers/usb/gadget/composite.c
> @@ -735,8 +735,21 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
> case USB_DT_DEVICE:
> cdev->desc.bNumConfigurations =
> count_configs(cdev, USB_DT_DEVICE);
> - cdev->desc.bMaxPacketSize0 =
> - cdev->gadget->ep0->maxpacket;
> +
> + /*
> + * If the speed is Super speed, then the supported
> + * max packet size is 512 and it should be sent as
> + * exponent of 2. So, 9(2^9=512) should be filled in
> + * bMaxPacketSize0. Also fill USB version as 3.0
> + * if speed is Super speed.
> + */
> + if (cdev->gadget->speed == USB_SPEED_SUPER) {
> + cdev->desc.bMaxPacketSize0 = 9;
> + cdev->desc.bcdUSB = cpu_to_le16(0x0300);
> + } else {
> + cdev->desc.bMaxPacketSize0 =
> + cdev->gadget->ep0->maxpacket;
> + }
> value = min(w_length, (u16) sizeof cdev->desc);
> memcpy(req->buf, &cdev->desc, value);
> break;
>
Applied, thanks
--
Best regards,
Marek Vasut
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